<!DOCTYPE html>
<html lang="ru">

<head>
    <title>Title 1</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
        div {
            width: 160px;
            height: 80px;
            padding: 20px;
            border: 8px solid red;
            background: yellow;
        }

        .content-box {
            box-sizing: content-box;
            /* Total width: 160px + (2 * 20px) + (2 * 8px) = 216px
     Total height: 80px + (2 * 20px) + (2 * 8px) = 136px
     Content box width: 160px
     Content box height: 80px */
        }

        .border-box {
            box-sizing: border-box;
            /* Total width: 160px
     Total height: 80px
     Content box width: 160px - (2 * 20px) - (2 * 8px) = 104px
     Content box height: 80px - (2 * 20px) - (2 * 8px) = 24px */
        }
    </style>
    <script>
        let a = 0;
    </script>
</head>

<body>
    <h1>Site 1</h1>
    <div class="content-box">Content box</div>
    <br />
    <div class="border-box">Border box</div>
</body>

</html>
<!-- [[html_min_edu]] -->